d12887.asm

来自「mt8880时钟芯片的Ｃ和汇编程序」· 汇编 代码 · 共 107 行

cs1   bit    p2.5
cs2   bit    p2.6
cs3   bit    p2.7
 org 00h
 AJMP   MAIN
 
    ORG    30H
main:
     mov sp,#6Ch
     mov  p0,#0ffh
     mov   p1,#0ffh
     mov   p2,#0ffh
     mov   p3,#0ffh
     init:
       mov p0,#0ffh

       setb     cs1

       mov dptr,#3f0dh
       mov a,#80h
       movx @dptr,a
       nop
       mov dptr,#3f0bh
       mov a,#82h
       movx @dptr,a
        nop
       mov dptr,#3f0ch
       mov a,#00h
       movx @dptr,a
        nop
	 MOV DPTR,#3f0AH  ;MC146818内部 A寄存器地址=0AH
	 MOV A,#20H	  ;选择时钟频率=32.768KHz
	 MOVX @DPTR,A	   ;无中断周期和SQW输出频率
        nop
       mov dptr,#3f09h
       mov a,#08h

       movx @dptr,a

       mov dptr,#3f08h
       mov a,#03h

       movx @dptr,a

       mov dptr,#3f07h
       mov a,#21h
       movx @dptr,a
       mov dptr,#3f06h
       mov a,#05h
       movx @dptr,a
        mov dptr,#3f05h
       mov a,#0FFh
       movx @dptr,a
        mov dptr,#3f04h
       mov a,#21h
       movx @dptr,a
        mov dptr,#3f03h
       mov a,#0FFh
       movx @dptr,a
        mov dptr,#3f02h
       mov a,#59h
       movx @dptr,a
        mov dptr,#3f01h
       mov a,#0FFh
       movx @dptr,a
        mov dptr,#3f00h
       mov a,#00h
       movx @dptr,a

       mov dptr,#3f0bh
       mov a,#02h
       movx @dptr,a

       ;clr cs1
     ;  setb p3.6
       ret
       read:
        clr   cs3
        clr  cs2
        setb cs1

        mov dptr,#3f00h
       movx a,@dptr
       MOV 50H,A
       mov dptr,#3f02h
       movx a,@dptr
       MOV 42H,A
       mov dptr,#3f04h
       movx a,@dptr
       MOV  45H,A
       mov dptr,#3f06h
       movx a,@dptr
       MOV B,A
       mov dptr,#3f07h
       movx a,@dptr
       MOV  48H,A
       mov dptr,#3f08h
       movx a,@dptr
       MOV 4BH,A
       mov dptr,#3f09h
       movx a,@dptr
       MOV  4EH,A

;       clr cs1
;       setb p3.7
        ret